Method of and apparatus for shearing and rolling metal billets

ABSTRACT

The ends of a metal slab or billet are sheared so as to impart a V-shaped convex lateral surface thereto. The shear blades are pressed into the metal in a pinching motion until the remaining uncut portion fractures and breaks through. The blades are slightly offset with respect to each other whereby the blades are not flattened when they reach the end of their stroke.

United States Patent Inventor Randolph N. Mitchell Richmond, Va.

Appl. No. 757,915

Filed Sept. 6, 1968 Patented June 22, 1971 Assignee Reynolds Metals Company Richmond, Va. 1

METHOD OF AND APPARATUS FOR SHEARING AND ROLLING METAL BILLEIS 5 Claims, 8 Drawing Figs.

US. Cl 72/203, 83/5 1 Int. Cl 8211: 1/00 Field of Search 72/204,

[56} References Cited UNITED STATES PATENTS 2,214,618 9/ 1940 Kenyon et al 72/203 X 2,712,169 7/1955 Buttress 83/51 X 3,416,347 12/1968 Walsh et a1. 83151 X 3,457,757 7/1969 Mathieu et al. 72/203 3,492,853 1/1970 Gross 83/51 Primary Examiner-Milton S. Mehr Attorney-Glenn, Palmer, Lyne, Gibbs and Thompson ABSTRACT: The ends of a metal slab or billet are sheared so as to impart a V-shaped convex lateral surface thereto. The shear blades are pressed into the metal in a pinching motion until the remaining uncut portion fractures and breaks through. The blades are slightly ofi'set with respect to each other whereby the blades are not flattened when they reach the end of their stroke.

METHOD OF AND APPARATUS FOR SHEARING AND ROLLING METAL BILLETS This invention relates to a method of and apparatus for shearing and rolling metal slabs or billets and more particularly to a method and apparatus which permits the rolling of a metal billet so as to avoid adverse end conditions known as fish mouthing and alligatoring.

In the preparation of aluminum sheet and plate it has been observed that an end condition develops in metal being rolled from billets to the desired thinner gauges thereof in the making of both sheet and plate items. The condition arises from the fact that the top and bottom surfaces of relatively thick metal in the form of either billet or slab are elongated considerably more than portions of the metal in its central zone. One such condition is customarily referred to as fish mouthing" and is so named because of a cusplike end condition that resembles somewhat an open mouth of a fish. A more severe condition, known sometimes as alligatoring results when an actual rupture of the rolled metal occurs substantially along the neutral axis of the metal. This condition, interestingly enough, is referred to as "crocodiling in Europe. Nevertheless, regardless of the name applicable thereto, the conditions are sufficiently serious, sometimes in cracks extending eight feet into the slab material, that large financial losses may ensue in that excessively large amounts of scrap metal are produced.

The present invention effectively overcomes all of these deleterious end conditions by treating the ends of metal billets or slabs in a special end shearing or cropping operation whereby the adverse effect caused by the tendency of the upper and lower surfaces to elongate is neutralized. Specifically, the slab or billet, while held stationary and preparatory to being fed into a rolling mill or the like, has its leading and trailing edges subjected to an end shearing or cropping operation by a pair of V-shaped blades which impart a convex lateral end surface to the ends of the metal. The conditions referred to above are applicable to metal slabs and billets having thicknesses of 4 inches and more which, when subjected to a rolling operation, have not been reduced sufficiently to convert the cast structure at the neutral axis area between the rolled surfaces to a worked condition which is not susceptible to fish mouthing or alligatoring.

The inherent advantages and improvements of the present invention will become more readily apparent upon considering the following detailed description of the invention and by reference to the drawings, in which:

FIG. 1 is a side elevational view, schematic in nature, illustrating passage of a billet or slab through cooperating rolls in a rolling mill;

FIG. 2 is a side elevation view, schematic in nature, illustrating the cutting apparatus of the present invention;

FIG. 3 is a side elevation view, partially in cross section and drawn to an enlarged scale, showing the position of the blades in the process of penetrating the billet;

FIG. 4 is a side elevation view partially in cross section as in FIG. 2, showing the position of the blades when the billet has been completely sheared;

FIG. 5 is a side elevation view of a sheared billet;

FIG. 6 is a side elevation view showing the preferred arrangement of the blades;

FIG. 7 is a side elevation view illustrating one end condition for a billet; and,

FIG. 8 is a side elevational view illustrating another end condition for a billet.

Referring now to FIG. 1, a slab or billet I0 is fed in the direction of the arrow into a plurality of work stations of a rolling mill, indicated generally at 12. Each station consists of cooperating upper rolls 13, 14 and lower rolls 15, 16. The slab or billet is provided with convex lateral leading surfaces 17, 18 in a manner to be described hereinafter. This leading end condition not only makes the entry of the slab or billet into rolls 13, 14, 15 and 16 easier but also minimizes the effects of fish mouthing and alligatoring.

Turning now to FIG. 2, an upper shear assembly is indicated generally at 20 and a lower shear assembly indicated generally at 22. Upper shear assembly 20 consists of an upper V-blade shear 24 retained in a holder 26 which is reciprocated by means of a ram or press element 28. Similarly, lower shear as sembly 22 consists of a lower V-blade shear 30 retained in holder 32 carried by a ram or press element 34. It is to be understood that either one of the upper shear assembly 20 or the lower shear assembly 22 may be held stationary while the other reciprocates in a conventional press or the like. A billet or slab 10 to be cut having a substantial thickness of 4 inches or more and is at rest on a table or bolster of a press.

In FIGS. 3 and 4 there is illustrated the details of the cooperating upper and lower V-blade shears 24, 30. Thus upper V-blade shear 24 is illustrated to have convex surfaces 38, 40 which extend laterally with respect to the billet or slab 10 to be cut. Stated with respect to the metal, the bottom surface of the V-blade extends transversely to the direction in which the metal is rolled. Similarly, the lower V-blade shear 30 is provided with convex surfaces 42, 44 which extend laterally of the billet or slab to be cut. The billet or slab I0 is illustrated to have an elongated top surface 46 and an elongated bottom surface 48. A crack 50 at the neutral axis of the billet or slab 10 may be either actually present or incipient.

The series of FIGS. 3, 4 illustrate the progressive stages of pressing the upper and lower V-blade shears 24, 30 into the slab or billet 10 until rupture occurs. In softer metal alloys, the blades may have to be pressed all the way through as illustrated in FIG. 4, but in the harder alloys the cropped end portion, indicated generally at 36, will fracture through prior to the completion of the stroke for the cooperating upper and lower V-blades 24, 30. The resultant slab has convex surfaces l7, l8 imparted thereto at the leading billet end and convex surfaces 17a, 17b imparted thereto at the trailing billet end, all of which surfaces extend transversely with respect to the direction in which the billet or slab is rolled.

An important feature of the present invention is illustrated in FIG. 6 wherein the upper and lower V-blade shears 24, 30 are offset by a distance designated D so that the points of the blades 24, 32 are not flattened when the metal is sheared through. A satisfactory offset distance D of up to one-eighth of an inch provides the desired results.

Reference to FIGS. 7 and 8 illustrate the adverse end conditions identified previously as fish mouthing and alligatoring. Specifically, in FIG. 7 a cusplike formation 52 located substantially centrally between elongated upper surface 46 and elongated bottom surface 48 of the billet 10 is illustrated in FIG. 7, and the more serious condition resulting therefrom illustrated in FIG. 8 of alligatoring wherein the cusp 52 between surfaces 46 and 48 results in a longitudinally extending crack 50in billet 26.

While the present invention is applicable to metals generally including aluminum and steel, it is especially adapted to be practiced in connection with aluminum and aluminum alloys wherein the fish mouthing and alligatoring problems are quite pronounced.

While presently preferred embodiments of the invention have been illustrated and described, it will be recognized that the invention may be otherwise variously embodied and practiced within the scope of the claims which follow.

What is claimed is:

1. An apparatus for shearing metal billet or the like comprising:

a. a pair of opposed V-shaped cutting blades, each of which terminates in a relatively sharp point,

b. and means for reciprocating said blades to impart a convex lateral surface to a metal billet being sheared,

c. said blades being slightly offset with respect to each other whereby the points of said blades are not flattened when said metal is sheared through.

2. An apparatus for shearing metal billet or the like as defined in claim 1 wherein said blades are offset with respect to each other in the direction in which the metal is to be rolled by approximately one-eighth of an inch.

claim 3 wherein said metal billet is selected from the group of aluminum and aluminum alloys.

5. A method of treating a metal billet or the like preparatory to rolling, said method comprising the steps of a. shearing an end of said billet to produce a V-shaped convex surface on the end of said metal billet, b. and inserting said end of said billet having said V-shaped convex surface into a series of cooperating rolls to effect a rolling of said metal billet. 

1. An apparatus for shearing metal billet or the like comprising: a. a pair of opposed V-shaped cutting blades, each of which terminates in a relatively sharp point, b. and means for reciprocating said blades to impart a convex lateral surface to a metal billet being sheared, c. said blades being slightly offset with respect to each other whereby the points of said blades are not flattened when said metal is sheared through.
 2. An apparatus for shearing metal billet or the like as defined in claim 1 wherein said blades are offset with respect to each other in the direction in which the metal is to be rolled by approximately one-eighth of an inch.
 3. A method of rolling a metal billet or the like having a thickness of at least four inches, said method comprising the steps of a. cutting the leading and trailing end of said billet to impart a V-shaped convex surface to the ends of said metal billet, b. inserting said V-shaped convex end of said billet into a series of cooperating rolls, c. and rolling said metal without developing fish mouthing or alligatoring of said metal.
 4. A method of rolling metal billet or the like as defined in claim 3 wherein said metal billet is selected from the group of aluminum and aluminum alloys.
 5. A method of treating a metal billet or the like preparatory to rolling, said method comprising the steps of a. shearing an end of said billet to produce a V-shaped convex surface on the end of said metal billet, b. and inserting said end of said billet having said V-shaped convex surface into a series of cooperating rolls to effect a rolling of said metal billet. 